Electrophysiological recordings were used to investigate the degree of pelvic/visceral convergent inputs onto single medullary reticular formation (MRF) neurons. A total of 94 MRF neurons responsive to bilateral electrical stimulation of the pelvic nerve (PN) in 12 urethane-anaesthetized male rats were tested for responses to mechanical stimulation of the urinary bladder, urethra, colon and penis, and electrical stimulation of the dorsal nerve of the penis (DNP) and abdominal branches of the vagus. Responses to distension of the bladder were found for 51% (n = 48) of the MRF neurons tested. Of these 48, 71% responded to urethral infusion, 81% responded to colon distension, 100% responded to penile stimulation (and DNP), and 85% responded to vagal stimulation, with 62% responding to stimulation of all four of these territories. This high degree of visceral convergence (i.e. 62%) in a subset of PN-responsive MRF neurons is significantly greater than for the subset of PN-responsive MRF neurons that did not respond to urinary bladder distension (i.e. out of the 46 remaining neurons, none responded to all four of the other pelvic/visceral stimuli combined). These results suggest that the neurons processing information from the urinary bladder at this level of the neural axis are likely to be important for mediating interactions between different visceral organs for the coordination of multiple pelvic/visceral functions. Normal functions related to the male pelvic/visceral organs, such as urination, defaecation, and ejaculation, involve coordination between the different organ systems. One example of a process in which coordination is important is ejaculation, which consists of emission of the seminal fluid from the ejaculatory ducts to the proximal urethra, bladder neck closure and anterograde ejaculation out of the proximal urethra (Seftel et al. 1991;Truitt & Coolen, 2002). Disruption of this coordination, such as following spinal cord injury, results in the failure of bladder neck closure and thus a subsequent retrograde ejaculation leading to infertility (Heruti et al. 2001).Another example in which coordination between the pelvic organs is important is during voiding of the urinary bladder, which requires contraction of the external anal sphincter, thereby preventing defaecation. In humans, distension of the urinary bladder produces contractions of the anal sphincter (Basinski et al. 2003). Experimental studies using cats have shown that distension of the urinary bladder both inhibits colonic contractions (Bouvier et al. 1990) and produces simultaneous contraction of the anal sphincter (Bouvier & Grimaud, 1984). The reverse also occurs, i.e. the urinary system is inhibited during defaecation. In humans, functional stimulation of the anal sphincter inhibits detrusor muscle contraction (Cheng et al. 2002). In animal studies, distension of the rectum has been shown to inhibit urinary bladder activity in female rats (Sugaya et al. 1998), and stimulation of colonic branches of the pelvic nerve in cats has been shown ...

Single medullary reticular formation (MRF) neurons receive ascending spinal inputs from multiple somatic and pelvic visceral territories. MRF neurons were examined for responses to both pelvic (PN) and vagus (abdominal branches: VAG-abd) nerve stimulation, which dually innervate certain pelvic viscera. Recordings in 12 urethane-anesthetized male rats were performed. Of 121 PN-responsive MRF neurons, 50% responded to VAG-abd. Twenty-seven (22%) responded to colonic distention. All 121 neurons responded to noxious stimulation of somatic territories, including many areas outside the perigenital region (including the hindpaws, ears, face). These data demonstrate input originating from different spinal and cranial nerves. The functional significance of this viscerosomatic convergence to MRF is unknown, but could relate to sensory/autonomic integration for coordinating multiple bodily functions, including reproductive and eliminative events.

Varying degrees of neurologic function spontaneously recovers in humans and animals during the days and months after spinal cord injury (SCI). For example, abolished upper limb somatosensory potentials (SSEPS) and cutaneous sensations can recover in persons post-contusive cervical SCI. To maximize recovery and the development/evaluation of repair strategies, a better understanding of the anatomical locations and physiological processes underlying spontaneous recovery after SCI is needed. As an initial step, the present study examined whether recovery of upper limb SSEPs after contusive cervical SCI was due to the integrity of some spared dorsal column primary afferents that terminate within the cuneate nucleus and not one of several alternate routes. C5-C6 contusions were performed on male adult rats. Electrophysiological techniques were used in the same rat to determine forelimb evoked neuronal responses in both cortex (SSEPS) and the cuneate nucleus (terminal extracellular recordings). SSEPs were not evoked 2 days post-SCI but were found at 7 days and beyond, with an observed change in latencies between 7 and 14 days (suggestive of spared axon remyelination). Forelimb evoked activity in the cuneate nucleus at 15 but not 3 days post-injury occurred despite dorsal column damage throughout the cervical injury (as seen histologically). Neuroanatomical tracing (using 1% unconjugated cholera toxin B subunit) confirmed that upper limb primary afferent terminals remained within the cuneate nuclei. Taken together, these results indicate Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access

In Jordan, the leaves of Laurus nobilis (Family Lauraceae) have been used in folk medicine for the treatment of diarrhea, among other ailments. However, the ethnopharmacology of this plant needs to be scientifically validated. The present work was carried out to evaluate the scientific basis of the antidiarrheal effect of the aqueous extract of L. nobilis leaf. L. nobilis leaf extract significantly inhibited castor oil-induced diarrhea (effective concentration producing 50% of the maximum response [EC(50)]=150±6.4 mg/kg) and reduced castor oil-induced enteropooling in rats (EC(50)=162±5.9 mg/kg). The extract also significantly inhibited intestinal transit of a charcoal meal and exerted a significant dose-dependent relaxation (EC(50)=71±5.3 mg/mL) on rat ileal smooth muscle. The aqueous extract tested positive for flavonoids, alkaloids, and tannins. These results established the efficacy of L. nobilis leaf aqueous extract as an antidiarrheal agent and are consistent with the popular use of the plant in the treatment of gastrointestinal disorders, particularly diarrhea.

The presence of pelvic visceral inputs to neurons in the rostral medulla that are responsive to electrical stimulation of the abdominal branches of the vagus nerve (VAG-abd) was investigated in a complete chronic T8 spinal transection rat model. Using extracellular electrophysiological recordings from single medullary reticular formation (MRF) neurons, 371 neurons in 15 rats responsive to pinching the ear (search stimulus) were tested for somato-visceral and viscero-visceral convergent responses to stimulation of the following nerves/territories: VAG-abd, dorsal nerve of the penis, pelvic nerve, distention of urinary bladder and colon, penile stimulation, urethral infusion, and touch/pinch of the entire body surface. In addition to these mechanical and electrical stimuli, a chemical stimulus applied to the bladder was assessed as well. Of the total neurons examined, 205 were tested before and 166 tested beginning 20 min after application of a chemical irritant (2% acetic acid) to the urinary bladder (same rats used pre/post irritation). As with intact controls, many ear-responsive MRF neurons responded to the electrical stimulation of VAG-abd. Although MRF neuron responses failed to be evoked with direct (mechanical and electrical nerve) pelvic visceral stimuli, acute chemical irritation of the urinary bladder produced a significant increase in the number of MRF neurons responsive to stimulation of VAG-abd. The results of this study indicate a central effect that potentially relates to some of the generalized below level pelvic visceral sensations that have been documented in patients with complete spinal cord injury.